Linux: Out-of-bounds Read
CVE-2026-64053 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions d18160c9525c63c203656fefd847e94b538cd4a4, 0d48654af4d1390c888389206cc13b51b82c30e6, 066be1439593a381b1a29663becfcfe0c92363e7 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.13% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to d18160c9525c63c203656fefd847e94b538cd4a4 or 0d48654af4d1390c888389206cc13b51b82c30e6 or 066be1439593a381b1a29663becfcfe0c92363e7 or 637ad3a56a3b889527d1dacea6fea2a8bd648140, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.92 or 6.18.34 or 7.0.11, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 3991657ae7074c3c497bf095093178bed37ea1b4 up to, but not including, d18160c9525c63c203656fefd847e94b538cd4a4; 3991657ae7074c3c497bf095093178bed37ea1b4 up to, but not including, 0d48654af4d1390c888389206cc13b51b82c30e6; 3991657ae7074c3c497bf095093178bed37ea1b4 up to, but not including, 066be1439593a381b1a29663becfcfe0c92363e7; 3991657ae7074c3c497bf095093178bed37ea1b4 up to, but not including, 637ad3a56a3b889527d1dacea6fea2a8bd648140; 6.11 | d18160c9525c63c203656fefd847e94b538cd4a4, 0d48654af4d1390c888389206cc13b51b82c30e6, 066be1439593a381b1a29663becfcfe0c92363e7, 637ad3a56a3b889527d1dacea6fea2a8bd648140 |
| Linux | Linux Kernel | 6.11 up to, but not including, 6.12.92; 6.13 up to, but not including, 6.18.34; 6.19 up to, but not including, 7.0.11; 7.1 | 6.12.92, 6.18.34, 7.0.11 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: block: don't overwrite bip_vcnt in bio_integrity_copy_user() bio_integrity_add_page() already sets bip_vcnt to 1 for the bounce segment. Overwriting it with nr_vecs breaks bip_vcnt <= bip_max_vcnt on WRITE (bip_max_vcnt is 1), so the gap-merge checks in block/blk.h read past the bip_vec[] flex array. On READ the read is in bounds but lands on a saved user bvec instead of the bounce. The line was added for split propagation, but bio_integrity_clone() doesn't copy bip_vcnt and BIP_CLONE_FLAGS excludes BIP_COPY_USER.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Out-of-bounds Read vulnerabilities
- 7.1 High severity
- 7.8 High severity
- 7.3 High severity
- 7.1 High severity
- 7.8 High severity
- 9.8 Critical severity
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